The objective of the proposed research is to elucidate the role of the brain stem neurons, particularly those of the superior colliculus, in the control of saccadic eye movements. These experiments are concerned, primarily, with three questions: 1) How, in a complex visual environment, is a particular target selected by the oculomotor system for foveal acquisition? 2) Does the superior colliculus participate in the generation of saccadic movements elicited by auditory stimuli and, if so, how are the auditory and visual inputs coordinated? 3) How do the functional properties of neurons at subsequent synaptic junctions differ from the properties of superior colliculus neurons? In a broader sense, results of these studies will be important in attempts to describe the neural events which intervene between the central processing of sensory information and the central programming of motor outputs.